Light guide plate, optical structure and associated electronic device

ABSTRACT

A light guide plate can include: a first end surface coupled to a reflection surface and a second end surface; where an incident light entering the light guide plate through the first end surface is reflected by the reflection surface and then output from the second end surface; and a diffusion structure configured to increase a transmission path of the incident light in the light guide plate.

RELATED APPLICATIONS

This application claims the benefit of Chinese Patent Application No.201810008333.7, filed on Jan. 4, 2018, and also claims the benefit ofU.S. Provisional Application No. 62/585,009, filed on Nov. 13, 2017,both of which are incorporated herein by reference in their entirety.

FIELD OF THE INVENTION

The present invention generally relates to communication technology, andmore particularly to light guide plates, optical structures, andassociated electronic devices.

BACKGROUND

As shown in FIGS. 1A, 1B and 1C, an example optical structure of theelectronic device can include sensor 820 and light guide plate 830. Thelight receiving surface of light guide plate 830 may be located belowthe light transmission opening of the frame of the electronic device.The light can enter from the light receiving surface, may transmitthrough light guide plate 830 to the light emitting surface, and canfinally reach sensor 820. This example optical structure can realize anarrow frame of the electronic device, such that the proportion of thedisplay portion can be increased. However, the surface of lightreceiving surface 810 of light guide plate 830 is a relatively smoothsurface, and light of some angles may not be transmitted to the sensorthrough the light guide plate. In the example of FIG. 1D, the field ofview (FOV) of the sensor receiving light may only be ±30°, which maymake the field of view of sensor 820 receiving light greatly differentfrom the ideal FOV, thereby reducing the accuracy of sensor 820.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B are perspective views of an example electronic deviceand example optical structure.

FIG. 1C is a perspective view of an example optical structure.

FIG. 1D is an example of the relationship between the incident angle andthe light intensity of light entering the example optical structure.

FIGS. 2A and 2B are perspective views of a first example electronicdevice and optical structure, in accordance with embodiments of thepresent invention.

FIG. 2C is a cross-sectional view of the first example electronic deviceand optical structure, in accordance with embodiments of the presentinvention.

FIG. 3A is a perspective view of the first example optical structure, inaccordance with embodiments of the present invention.

FIGS. 3B, 3C, and 3D are cross-sectional views of the first exampleoptical structure and an example transmission path of light of differentincident angles, in accordance with embodiments of the presentinvention.

FIG. 3E is an example of the relationship between the incident angle andthe light intensity of the light entering the first example opticalstructure, in accordance with embodiments of the present invention.

FIG. 4 is a perspective view of a second example optical structure, inaccordance with embodiments of the present invention.

FIG. 5 is a perspective view of a third example optical structure, inaccordance with embodiments of the present invention.

FIG. 6 is a perspective view of a fourth example optical structure, inaccordance with embodiments of the present invention.

DETAILED DESCRIPTION

Reference may now be made in detail to particular embodiments of theinvention, examples of which are illustrated in the accompanyingdrawings. While the invention may be described in conjunction with thepreferred embodiments, it may be understood that they are not intendedto limit the invention to these embodiments. On the contrary, theinvention is intended to cover alternatives, modifications andequivalents that may be included within the spirit and scope of theinvention as defined by the appended claims. Furthermore, in thefollowing detailed description of the present invention, numerousspecific details are set forth in order to provide a thoroughunderstanding of the present invention. However, it may be readilyapparent to one skilled in the art that the present invention may bepracticed without these specific details. In other instances, well-knownmethods, procedures, processes, components, structures, and circuitshave not been described in detail so as not to unnecessarily obscureaspects of the present invention.

In one embodiment, a light guide plate can include: (i) a first endsurface coupled to a reflection surface and a second end surface; (ii)where an incident light entering the light guide plate through the firstend surface is reflected by the reflection surface and then output fromthe second end surface; and (iii) a diffusion structure configured toincrease a transmission path of the incident light in the light guideplate.

Referring now to FIGS. 2A and 2B, shown are perspective views of a firstexample electronic device and optical structure, in accordance withembodiments of the present invention. Referring also to FIG. 2C, shownis a cross-sectional view of the first example electronic device andoptical structure, in accordance with embodiments of the presentinvention. In FIG. 2B, electronic device 900 can include housing 910 andoptical structure 100. Housing 910 may have light transmission opening911, which can be located at an upper edge of housing 910. Opticalstructure 100 can be located inside housing 910, and below lighttransmission opening 911. Optical structure 100 can include light guideplate 110 and sensor 120. For example, the front surface of electronicdevice housing 910 may be a transparent glass plate, and an opaqueregion can be disposed at an edge of the glass plate for shielding theinternal device. Light transmission opening 911 may be disposed on theopaque region to enable light to enter sensor 120 inside housing 910through light transmission opening 911. Also, the light emitted fromsensor 120 can be output externally through light transmission opening911.

Referring now to FIG. 3A, shown is a perspective view of the firstexample optical structure, in accordance with embodiments of the presentinvention. Referring also to FIGS. 3B, 3C, and 3D, shown arecross-sectional views of the first example optical structure and anexample transmission path of light of different incident angles, inaccordance with embodiments of the present invention. Here, opticalstructure 100 can include light guide plate 110 and sensor 120. Lightguide plate 110 can include end surface 111, reflection surface 112, endsurface 113, and diffusion layer 114. Light can be transmitted betweenend surfaces 111 and 113 through reflection surface 112. For example,the light of the external environment may enter light guide plate 110through diffusion layer 114 located at end surface 111, can be reflectedby reflection surface 112 of light guide plate 110 to end surface 113,and then may be transmitted into sensor 120. Reflection surface 112 canbe a flat surface, or other suitable shaped surface, such as a curvedsurface. Further, the angle between reflection surface 112 and endsurface 111 is an acute angle, the angle between reflection surface 112and end surface 113 is an acute angle (e.g., 45°), and the two acuteangles may be mutually complementary angles.

End surface 113 of light guide plate 110 and end surface 111 of lightguide plate 110 can be perpendicular to each other. Light can enterlight guide plate 110 from end surface 111 be transmitted to reflectionsurface 112 of light guide plate 110 to perform one reflection and thenemitted out from end surface 113. End surface 111 of light guide plate110 may be disposed below light transmission opening 911. Diffusionlayer 114 can scatter light in light guide plate 110. Diffusion layer114 can be a haze layer formed on light guide plate 110 or an opticaldiffusion layer. Light guide plate 110 can be made of a material havinga refractive index of more than 1. For example, light guide plate 110can be made of a plastic material having a refractive index of fromabout 1.4 to about 1.6. Sensor 120 can be located at end surface 113 oflight guide plate 110 and can be in close proximity to reflectionsurface 112 for receiving light transmitting from end surface 113 oflight guide plate 110. Sensor 120 can include at least one of an ambientlight sensor, a proximity light sensor, and a distance sensor.

In the example of FIGS. 3B, 3C, and 3D, diffusion layer 114 can belocated on end surface 111 of light guide plate 110, and light may enterlight guide plate 110 from end surface 111 through diffusion layer 114.The light can pass through reflection surface 112 and be reflected, thenbe transmitted to end surface 113, and may finally reach sensor 120.Diffusion layer 114 located at end surface 111 can increase the lightpath range entering end surface 111. For example, light that is at anangle with end surface 111 can enter light guide plate 110 throughdiffusion layer 114 located at the end surface 111, and may be dividedinto light in a plurality of directions due to the diffuse reflection.Thus, the range of the field of view (FOV) of sensor 120 of opticalstructure 100 can be increased, and the accuracy of the sensor for lightanalysis may be improved.

In some examples, diffusion layer 114 can be located on reflectionsurface 112, or diffusion layer 114 can be located on both reflectionsurface 112 and end surface 111, such that the light reflected byreflection surface 112 can be scattered to increase the range of the FOVof sensor 120 of optical structure 100. In other examples, diffusionlayer 114 may be replaced by adding a diffusion medium in light guideplate 110, or the diffusion medium can be added to the light guide platewith diffusion layer 114. Light guide plate 110 to which the diffusingmedium is added can increase the light path entering end surface 111,and the range of the FOV of sensor 120 of optical structure 100 can beincreased, such that the accuracy of the sensor for light analysis isimproved.

Referring now to FIG. 3E, shown is an example of the relationshipbetween the incident angle and the light intensity of the light enteringthe first example optical structure, in accordance with embodiments ofthe present invention. In this particular example, the curves a, b, c,d, e, and f respectively represent light intensity curve of an idealcase, a 99% haze surface case, a 95% haze surface case, a 90% hazesurface case, a 50% haze surface case, and a smooth surface case. Also,the horizontal axis may indicate the FOV of sensor 120, and the verticalaxis may indicate the light intensity. In this example, the higher thedegree of haze of end surface 111, the larger the range of the FOV ofsensor 120. Further, the haze of end surface 111 of light guide plate110 can increase the light path to increase the range of the FOV ofsensor 120 receiving light. In particular embodiments, light guide plate110 can introduce light into and out of sensor 120. By installingreflection surface 112 and diffusion layer 114 on light guide plate 110,the range of the FOV of sensor 120 receiving light can be increasedwithout expanding the light transmission opening. The detection accuracyof sensor 120 can be improved, and the associated facilitation of anarrow frame of electronic device 900 may improve the user experience.

Referring now to FIG. 4, shown is a perspective view of a second exampleoptical structure, in accordance with embodiments of the presentinvention. In this particular example, optical structure 200 can includelight guide plate 210 and sensor 220. Light guide plate 210 can includea first end surface, reflection surface 212, end surface 213, anddiffusion layer 214. In this particular example, receiving light branch210 a and emitting light branch 210 b may be included in the opticalstructure. The first end surface of light guide plate 210 can includereceiving light portion 211 a and emitting light portion 211 b.Receiving light portion 211 a can be included by receiving light branch210 a, and emitting light portion 211 b may be included by emittinglight branch 210 b. Diffusion layer 214 can be located on at least oneof receiving light portion 211 a and emitting light portion 211 b. Inthis example, diffusion layer 214 can be located on receiving lightportion 211 a, and emitting light portion 211 b and reflection surface212 may be smooth surfaces.

In this example, when sensor 220 of optical structure 200 is both anambient light sensor and a proximity light sensor, or sensor 220 ofoptical structure 200 is both an ambient light sensor and a distancesensor. The proximity light sensor or the distance sensor can include alight-emitting element. The ambient light sensor can be installed on aposition of end surface 213 adjacent to receiving light branch 210 a andreflection surface 212 for receiving light emitted from end surface 213.The light-emitting element can be installed on a position of end surface213 adjacent to emitting light branch 210 b and reflection surface 212for emitting light to end surface 213.

Receiving light branch 210 a and emitting light branch 210 b can bearranged side by side in the same plane, and receiving light branch 210a may be utilized for receiving external ambient light or lightreflected by the object. Emitting light branch 210 b may be utilized fortransmitting the light emitted by the light-emitting element to anexternal object. For example, light can enter from the outside intolight guide plate 210, pass through diffusion layer 214 of receivinglight portion 211 a of the first end surface, and be transmitted to theambient light sensor, such that the range of the FOV of the ambientlight sensor receiving light can be increased. In addition, the lightemitted by light-emitting element can be emitted from emitting lightportion 211 b of the first end surface. In order to ensure the FOV ofthe sensor receiving light, the light emitted from the light-emittingelement can be prevented from being reflected by diffusion layer 214 inorder to form an interference light source. This can substantially avoida reflection signal of the actual object from being disturbed and/ormisjudged.

Further, receiving light branch 210 a and emitting light branch 210 bcan be arranged side by side in the same plane and may be connected bysupport column 215. Support column 215 can separate receiving lightbranch 210 a and emitting light branch 210 b. As such, the interferencebetween receiving light portion 211 a and emitting light portion 211 bcan be substantially avoided. Also, light emitted from thelight-emitting element can be prevented from being reflected bydiffusion layer 214 to form an interference light source, therebypreventing the reflection signal of the actual object from beingdisturbed and possibly causing misjudgment.

Referring now to FIG. 5, shown is a perspective view of a third exampleoptical structure, in accordance with embodiments of the presentinvention. In this particular example, optical structure 300 can includelight guide plate 310 and sensor 320. Light guide plate 310 can includeend surface 311, reflection surface, end surface 313, and diffusionlayer 314. In this particular example, end surface 313 of light guideplate 310 may be parallel to end surface 311, and reflection surface oflight guide plate 310 can include reflection surfaces 312 a and 312 b.For example, reflection surfaces 312 a and 312 b can be parallel andopposite to each other. Also, the angle between reflection surface 312 aand end surface 313 can be, e.g., 135°, and the angle between reflectionsurface 312 b and end surface 313 can be, e.g., 45°. The light in lightguide plate 310 can be reflected by reflection surfaces 312 a and 312 b,respectively; that is, the light can be reflected twice. The lightentering through end surface 311 may be output from end surface 313after being sequentially reflected by reflection surfaces 312 a and 312b.

In this particular example, diffusion layer 314 of light guide plate 310of optical structure 300 can be located on at least a portion of endsurface 311 of light guide plate 310, or can be located on at least aportion of reflection surface 312 a or reflection surface 312 b of lightguide plate 310. This can increase the light path entering end surface311, and the range of the FOV of sensor 320 of optical structure 300,thereby improving the accuracy of the sensor for light analysis.

Referring now to FIG. 6, shown is a perspective view of a fourth exampleoptical structure, in accordance with embodiments of the presentinvention. In this particular example, optical structure 400 can includelight guide plate 410 and sensor 420. Light guide plate 410 can includereceiving light branch 410 a, emitting light branch 410 b, and commonbody 410 c. A first portion of common body 410 c can connect toreceiving light branch 410 a and a second portion of common body 410 ccan connect to emitting light branch 410 b. Further, receiving lightbranch 410 a can be integrally formed with a first portion of commonbody 410 c, and emitting light branch 410 b may be integrally formedwith a second portion of common body 410 c. End surface 411 of lightguide plate 410 can include receiving light portion 411 a by receivinglight branch 410 a, and emitting light portion 411 b by emitting lightbranch 410 b (collectively, end surface 411). Reflection surface 412 oflight guide plate 410 can include portion 412 a on receiving lightbranch 410 a, and portion 412 b on emitting light branch 410 b(collectively, reflection surface 412).

Reflection surface 413 and end surface 414 of light guide plate 410 canbe included in common body 410 c. For example, and surface 414 may beparallel to end surface 411. Reflection surface 412 can be parallel toand opposite to reflection surface 413, and the angle between reflectionsurface 412 and end surface 414 is, e.g., 135°, while the angle betweenreflection surface 413 and end surface 414 is, e.g., 45°. The lightentering light guide plate 410 from end surface 411 can be sequentiallyreflected by reflection surface 412 and reflection surface 413, andoutputted from end surface 414. In some examples, the light can alsoenter light guide plate 410 from end surface 414, be sequentiallyreflected by reflection surface 413 and end surface 411, and then beoutputted from end surface 411. Diffusion layer 416 can be installed onat least one of receiving light portion 411 a and emitting light portion411 b of end surface 411. In this example, diffusion layer 416 isinstalled on receiving light portion 411 a.

For example, when sensor 420 of optical structure 400 is both an ambientlight sensor and a proximity light sensor, or sensor 420 of opticalstructure 400 is both an ambient light sensor and a distance sensor, thesensor can include a light-emitting element, and the ambient lightsensor can be installed on a position of end surface 414 adjacent toreceiving light branch 410 a and reflection surface 412 for receivinglight emitted from end surface 414. The light-emitting element can beinstalled on a position of end surface 414 that is adjacent to emittinglight branch 410 b and reflection surface 412 for emitting light to endsurface 414.

Receiving light branch 410 a and emitting light branch 410 b may bearranged side by side in the same plane. Receiving light branch 410 acan receive external ambient light, and emitting light branch 410 b maytransmit light emitted from the light-emitting element to an externalobject. For example, the light entering from outside into light guideplate 410 can pass through diffusion layer 416 of receiving lightportion 411 a of end surface 411, and be transmitted to the ambientlight sensor, such that the range of the FOV of the ambient light sensorreceiving light is increased. The light emitted from light-emittingelement can be emitted from emitting light portion 411 b of end surface411. Since emitting light portion 411 b has no diffusion layer in thiscase, the light emitted from the light emitting element can be preventedfrom being reflected by diffusion layer 416 to form an interferencelight source, thereby preventing the reflection signal of the actualobject from possibly being disturbed and causing misjudgment.

In addition, receiving light branch 410 a and emitting light branch 410b can be connected by support column 415. Support column 415 canseparate receiving light branch 410 a from emitting light branch 410 b,thereby avoiding mutual interference between receiving light portion 411a and emitting light portion 411 b. This can also prevent the lightemitted from the light-emitting element from being reflected bydiffusion layer 416 to form an interference light source, therebypreventing a reflection signal of the actual object from potentiallybeing disturbed and causing misjudgment.

In particular embodiments, an optical structure can include a lightguide plate and a sensor, and the light path entering a first endsurface may be increased by a diffusion layer of the light guide plate.Also, a range of FOV of an optical structure sensor receiving light canbe increased, thereby improving the accuracy of the sensor for lightanalysis. When the sensor of the optical structure is both an ambientlight sensor and a proximity light sensor, or the sensor of the opticalstructure is both an ambient light sensor and a distance sensor, thesensor can include a light-emitting element. The first end surface ofthe light guide plate can include a receiving light portion and anemitting light portion. The diffusion layer may be located on thereceiving light portion, and the emitting light portion and thereflection surface can be relatively smooth surfaces. The light enteringinto the light guide plate from outside may pass through the diffusionlayer of the receiving light portion of the first end surface, and betransmitted to the ambient light sensor, in order to increase the rangeof FOV of the ambient light sensor receiving light.

Light emitted from the light-emitting element may all be emitted fromthe emitting light portion of the first end surface. In order to ensurethe FOV of the sensor receiving light, the light emitted from thelight-emitting element can be prevented from being reflected by adiffusion layer to form an interference light source. This cansubstantially avoid a reflection signal of an actual object frompossibly being disturbed and/or misjudged. In addition, when thediffusing medium is added to the light guide plate, the light pathentering the first end face can be increased, and a range of the FOV ofan optical structure sensor receiving light may be increased, therebyimproving the accuracy of the sensor for light analysis.

The embodiments were chosen and described in order to best explain theprinciples of the invention and its practical applications, to therebyenable others skilled in the art to best utilize the invention andvarious embodiments with modifications as are suited to particularuse(s) contemplated. It is intended that the scope of the invention bedefined by the claims appended hereto and their equivalents.

What is claimed is:
 1. A light guide plate, comprising: a) a first endsurface coupled to a reflection surface and a second end surface,wherein said second end surface is perpendicular to said first endsurface; b) wherein an incident light entering said light guide platethrough said first end surface is reflected by said reflection surfaceand then output through said second end surface; c) a diffusionstructure on at least one of said first end surface and said reflectionsurface wherein an angle between said reflection surface and said secondend surface is an acute angle, and said reflection surface is separatedfrom said first end surface; d) a receiving light branch, wherein saidfirst end surface comprises a receiving light portion within saidreceiving light branch; and e) and an emitting light branch, whereinsaid first end surface comprises an emitting light portion within saidemitting light branch, wherein light to be emitted enters said emittinglight branch through said second end surface, and is emitted from saidlight guide plate through said emitting light portion.
 2. The lightguide plate of claim 1, wherein said diffusion structure comprises atleast one of a diffusion layer on a surface of said light guide plate,and a diffusion medium located inside said light guide plate.
 3. Thelight guide plate of claim 1, wherein said receiving light branchcomprises said diffusion structure.
 4. The light guide plate of claim 1,wherein said receiving light branch and emitting light branch areindependent and separated from each other.
 5. The light guide plate ofclaim 1, further comprising a support column that connects saidreceiving light branch and said emitting light branch.
 6. The lightguide plate of claim 3, wherein said diffusion structure is located onsaid receiving light portion of said first end surface.
 7. The lightguide plate of claim 1, wherein said diffusion structure is located onat least portion of said reflection surface.
 8. The light guide plate ofclaim 1, wherein an angle between said reflection surface and said firstend surface is a first acute angle, and said angle between saidreflection surface and said second end surface is a second acute angle.9. The light guide plate of claim 8, wherein said first acute angle andsaid second acute angle are mutually complementary.
 10. The light guideplate of claim 9, said first acute angle and said second acute angle areboth 45°.
 11. The light guide plate of claim 1, wherein said diffusionstructure comprises a haze layer formed by processing on said lightguide plate.
 12. The light guide plate of claim 1, wherein saiddiffusion structure comprises an optical diffusion layer.
 13. An opticalstructure, comprising the light guide plate of claim 1, and furthercomprising a sensor that receives said incident light through saidsecond end surface of said light guide plate.
 14. The optical structureof claim 1, further comprising a sensor having a light-receiving elementand a light-emitting element, wherein said light-receiving elementreceives said incident light through said second end surface, and saidlight-emitting element provides said light to be emitted to said secondend surface.
 15. A light guide plate, comprising: a) a first end surfacecoupled to a reflection surface and a second end surface, wherein saidsecond end surface is perpendicular to said first end surface; b)wherein an incident light entering said light guide plate through saidfirst end surface is reflected by said reflection surface and thenoutput through said second end surface; and c) a diffusion structure onat least one of said first end surface and said reflection surface,wherein an angle between said reflection surface and said first endsurface is a first acute angle, said angle between said reflectionsurface and said second end surface is a second acute angle, and saidfirst and second acute angles are mutually complementary.